Spontaneous vesiculation.

The thermodynamics of vesicle formation was analyzed by using the elastic bending energy approach. Several different possibilities of spontaneous vesiculation, due to soft bilayers, non-zero spontaneous curvature and Gaussian curvature, respectively, were presented and discussed. Intermediate structures in the closed vesicle-disklike mixed micelle phase transition could be either cup-like particles or open bilayers partially rolled into lipid tubules.